Signal storage device of the magnetron type



Dec. 10, 1957 A. M. SKELLETT SIGNAL STORAGE DEVICE OF THE MAGNETRON TYPEFiled Dec. 21. .1953

ooeoobeoea 000000000 2 Sheets-Sheet l I i l I I I INVENTOR. 4255/27 MSKELLETT Dec. 10, 1957 A. M. SKELLETT SIGNAL STORAGE DEVICE OF THEMAGNETRON TYPE 2 Shee ats-Sheet 2 Filed Dec. 21, 1953 Union ElectricCorporation, Hatboro, Pa., a corporation of Delaware ApplicationDecember 21, 1953, Serial No. 399,318

4 Claims. (Cl. 250-27) This invention relates to signal storage systemsand apparatus.

A principal object of the invention is to provide a novel form of signalstorage system employing a magnetron as the storage device.

Another object is to provide a magnetron and associated circuits wherebythe magnetron can be pulsed to two different persisting stableconditions.

A feature of the invention relates to a novel pulse-controlled keyingsystem employing a simplified magnetron device and a novel combinationof associated magnetic field producing elements.

Another feature relates to the combination of a magnetron tube of thetwo-element cathode and concentric anode type, having three magneticfield producing elements, one of which is arranged to be energized by anapplied signal pulse to switch the magnetron to either of two differentpersisting stable conditions.

A further feature relates to an improved and simplified pulse-controlledmagnetron keyer.

A still further feature relates to the novel organization, arrangement,and relative location and interconnection of parts which cooperate toprovide an improved magnetron signal storage system.

Other features and advantages, not specifically enumerated will beapparent after a consideration of the following detailed descriptionsand the appended claims.

In the drawing, which shows by way of example certain preferredembodiments:

Fig. 1 is a graph explanatory of the invention;

Fig. 2 is a perspective View of one form of device according to theinvention;

Fig. 3 is a schematic wiring diagram of the device;

Fig. 4 is another view of the device of Fig. 2;

Fig. 5 shows a modification of the device;

Fig. 6 shows a portion of a typical impulse counting system embodyingcertain features of the invention;

Fig. 7 is a graph used in explaining the operation of Fig. 6.

I have discovered that a magnetron of the coaxial cathode andsurrounding cylindrical anode kind can be made to have two stablepersisting anode current conditions. I have also found that these twostable persisting conditions can be pulse-controlled by incorporating aplurality of magnetic field producing elements, one of which is a coilwhich can be connected to a source of electric pulses. Thus, referringto Fig. 1, there is shown in graph form the relation between theresultant magnetizing field acting on the electrons between theconcentric cathode and anode, and the anode current conditions. When theresultant magnetic field has a value H the plate current assumes apersistent steady value at approximately zero. On the other hand, whenthe resultant magnetic field has a smaller value H the anode or platecurrent persists at an entirely different steady value. In accordancewith the invention, these two stable persisting conditions arecontrolled by a momentary signal pulse which cooperates to trigger thenite States Patent T ice desired resultant magnetic field so as todetermine which one of the persisting stable conditions is to exist.

In accordance with the invention, the magnetron tube is designed and issupplied with the necessary cathode and anode direct current potentialswhich, however, remain at their preset design values for both of thestable operating conditions. The switching from one condition to theother is controlled entirely by an input signal pulse which modifies andtriggers the magnetic field from one value to the other, but Withoutchanging the applied potentials on either the cathode or anode. Theinvention, therefore, is clearly distinguishable from any magnetronsystem wherein the anode or plate current is keyed on or off by changingthe bias or operating potentials of the magnetron electrodes.

Referring to Fig. 2, the device comprises an evacuated bulb 10 of glassor other similar non-magnetic material. Suitably mounted within the bulbis a linear, and preferably cylindrical, electron emitting cathode 11.Coaxially surrounding cathode 11 is a cylindrical plate or anode 12.Cathode 11 may be of any construction well known in the electron tubeart, comprising, for example, a tubular cylindrical metal sleeve whichcan be raised to electron emitting temperature by a suitable heaterelement 13 which is schematically illustrated in Fig. 3, and which maybe a filament mounted on the interior of, but elec: trically insulatedfrom, the sleeve 11. Preferably a heater element 13 is of a type whichis non-inductive or at least has negligible external magnetic field whenconnected to a suitable source of filament heating current. The externalsurface of sleeve 11 has a coating of electron emissive material of anykind well known in the electron tube art.

Respective lead-in members or wires are provided for the various tubeelements, and are sealed for example through the base or header portionof bulb 10. Thus, wires 14 and 15 are connected to the ends of thecathode heater 13; the wire 16 is connected to the cathode sleeve 11;and the wire 17 is connected to the cylindrical plate or anode 11. Thebulb 10 with its electrodes is enclosed in a coil structure consisting,according to one embodiment, of three separate coil windings 18, 19, 20,to form a composite tubular assembly unit indicated in Fig. 2 by thenumeral 21, so that this plural coil unit can be telescoped over thebulb 10 as shown. The three coils of the unit 21 can be wound in theform of superposed coil windings and the relations of these windings, sofar as the directions of the coil turns, is schematically illustrated inFig. 4 by the conventional dot and cross symbols. Merely for simplicity,these coils are shown in Fig. 4 as each being of a single layer type. Itwill be understood, of course, that each coil is of the desired numberof turns either in a single layer or in a multi layer. Each of the coilshas a pair of individual supply leads; for example, the supply leads forthe coil 18 are designated by the numerals 22, 23. The supply leads forthe coil 19 are designated by the numerals 24, 25, and the supply leadsfor the coil 20 are designated by the numerals 26, 27.

The coil 18is connected in series with the direct current anode supplysource 28. The coil 19 is connectedv directly in circuit with the directcurrent supply source 28 so as to have a steady direct current flowingtherethrough. The coil 20 is connected to any suitable source 29 ofsignal pulses. As a result of the coaxial arrangement of the coilwindings and the similar coaxial relation of the electrodes 11 and 12,there is produced by each of the coils a magnetic field having acomponent located between the cathode and anode and extending parallelto the length of the cathode.

In accordance with one feature of the invention, the; I coil 19 isconnected in series withthe source 28 so as- Patented Dec. 10, 1957 togive to the said axial component of the magnetic field a-value H andatthe same time to apply a direct current potential across the anode 12and cathode 11, whereby the anode current remains at substantially zerovalue, as illustrated in Fig. 1. Under this condition, of course, thecoil 18 is deenergized and it is assumed that the coil 20 is alsodeenergized. The plate or anode current of the tube 10,,therefore,remains at this steady zero value, until a suitable input pulse isapplied to the winding 20 of such a polarity as to produce aninstantaneous field which opposes the steady field produced by coil 19.The instant that this occurs, plate current begins to How betweenelectrodes 12 and 11 and, therefore, this-same current flowsthroughwinding 18.

Because of the opposed winding; relations of the coils 18 and 19, whencurrentdoes flow between the anode 12 and the cathode. 11 through: the.tube and, therefore, through the coil 18, the magnetic field of the coil18, considered axially along the cathode 11, is in a reverse directionto the correspondingfield produced by coil 19 so that the field of onecoil. substantially cancels the field of the other, thus allowing the.current between anode 12 and cathode 11 to. fiow steadily at the higherstable value represented inFig. 1. Thiscondition persists until a pulseof .the opposite. polarity, is applied to wind-- ing 20 from source 29'.At theinstant of this pulse. thefield produced by windingltl' aidsihatproduced by. winding 19 so that plate currentirnmediately ceases to flowbetween electrodes 12 and 11,,and thus winding 18 immediately becomesdeenergized. Therefore, the cessation of plate current persists. evenafter the said pulse is applied, to winding 20.

Instead of using-an electromagnetic coil'19'to produce the steadycomponent ofmagnetic field parallel-to. the cathode 11, thiscoil may bereplaced by a permanent magnet 30 having pole pieces 31, 32, locatedadjacent opposite ends of the cathode external of the bulb 101 Theorientation .of the. field. of this permanent magnet .is suchthat-the.permanent magnetic field therefrom extends. parallel to=the cathode.11in. the opposite direction to the field produced by coil 18. Thus, inthe particular schematic arrangementiofthe. windings shown in Fig. 5,the coil 18,- whenenergized by the -battery 28, asa result of plate.current flow, produces amagnetic. fieldin the direction of the dottedline arrow, whereas the-permanent magnet 20 produces a fieldin the:direction-of the dotdash line arrow.

Since the theory of operation ofthe simple coaxial cathode andcylindrical plate magnetron tube is well known, a. detailed descriptionthereof is: not believed necessary hereirn:

It will bev seenfrom the foregoing thatthe magnetron as describedhereincan be caused'to assume two different steady. platercurrentconductive. states by applying-a momentary pulse of. the properpolarity'to the winding 20. This enables the device to beused in any,well known signal storage system, since theplate current-condition ofthe tubeltk-respondstothe polarity of' the pulse applied from [source 29andit .persists even after-the pulse is terminated.

Referring to Fig. ,6, there isshown one-typical storage or impulsecounting system embodyingja: tube-arrangement such asdcscribedhereinabove. In'-Fig. 6-,.the parts -or elementsvwhichr are "the same asthose of- Figs. l-S. bears the same-.designation numerals;- Thus, thereis shownin Fig. 6 a.portion'of-a iing counting system of the genericWynn-Williams typesuch as described for examplein-Proceedings. ofthenRoyal Society, A132, 295-31 (193-1). Merely, for simplicity, only:three counting stages are shown, but a greater or less number maybeemployed; Each stageincludes a magnetron tube 10 105,, etc.,. each oneofithese rtubesibeing similar to tube 10 of Figs. 2-5. E-ach lmagnetronhas surrounding it in coaxial f relationfourmagnetic field producingwindings, three---ofthese windi'ngs,-- for example winding- 'thewindings 33 33 33 ,v etc.

18 19 20 corresponding respectively to the windings 18, 19 and 20' ofFigs. 2, 3 and 4. These windings are designated by the same n'umeral asthose of Figs. 2-4 but with appropriate numerical subscripts, thus thecorresponding windings for the second stage are designated 18 19 20 andfor thethird stage 18 19 20 Each magnetron tube has a fourth winding33,, 33 33 etc., wound coaxiall'y with the remaining set of threewindings. All of these fourth windings are connected in parallel to aline 34 over which are received the impulsesto be counted.

The arrangement of the circuit connections is such that when one tube,for example tube 10 is plate current conductive'at its higher stablecondition as represented by the stable state #2 (Fig. 7) the nextsucceeding tube, namely tube 10 is in its lower state #1, but is primedready to be shifted to the higher stable state when the next impulse tobe counted is received over line 34. Coincident with the priming of saidnext succeeding tube, the tube next preceding tube 10 is shifted to itslower stable condition.- The priming pulse for any given magnetron isobtained from a change in the stable conducting state of the nextpreceding magnetron. Once a magnetron tube has been primed, the receiptof the next impulse from line 3 4causes that particular primed tube tochange from its lower stable state #1 toits higher stable state #2. Indoing so, the next succeeding magnetron tube, for example tube 10 .inthe chain is then primed. The windings 33 33 335, etc., can beconsidered as the firing windings; that is, they change the associatedmagnetron fromit s primed condition to its upper stable fired condition.The windings 19 192,19 are the priming windings; the windings 18,, 1'818 ,'are the locking or holding windings which are energized by thesteady plate current flow of theassociated magnetron when-it" is' in itshigher or #2 stable condition. The windings 20 20 20 are the defiringwindings for restoring the associated tube to its lower stable andunprimed condition.

For purposes ofexplanation, let it be assumed that at the moment, tube10 is in the conducting state at its higher stable valueas representedby the flat or horizontal portion of the graph in 'Fig. 7. This meansthat under this condition the resultant magnetic field acting ontheelectrons between the linear cathode and the surrounding tubular anodeof tube 10' has the value H Tube 10 which has been meanwhile primed, hasa resultant magnetic field represented'by the'value H and tube 10 and,of course, all the succeeding similar tubes in the chain or ring .havenot as yet been primed and have a resultant fieldH It-will now beassumedthat an impulse is received onthe line 34 which'energize's allThis impulse will have no effect on the electron discharge in tube 10,since its magnetic effect will be simply to move the li'n'eH to wardsthe left without changing the stable conductive state of tube 10 Fortube 10 however, the energi'z'ation of winding 33;, :willcause theeffective magnetic field to move from value H, to H and tube 10 willthus be energized or fired, that is, the electrons will flow from thecathode to the anode. happens, a pulse of current flows through theprimary winding 35,, .of'transformer 36 The secondary offithistransformer is connected in circuit with the defiring? winding20 of tube10 As aresult of this momentary energization'of-winding 20 the effectivemagnetic field acting -on tube 10 'will change from value H toapproximately H Immediately that this'happens, the field-from theholding or locking winding 18 -disappears and the field that is leftwhen the' pulse passes through -zerois equal to: H thus the tube 10 isdefired while the tube is fi'red and'the' tube 10% 'is primed. Arectifier 37 At the instant that this" The discharge has thus beentransferred under control of the received impulse from tube #1 to tube#2, and the discharge current flowing through coil 19;, 19 of tubeprimes the tube 10 so that it will be ready to be fired in response tothe next received impulse over line 34.

It will be understood that each of the windings 19 19 19 is connected tothe primary windings of a corresponding transformer similar totransformer 36; and the corresponding elements of these transformers andthe associated rectifiers are designated by the same numeral with theappropriate subscript. In order to complete the ring, the last stage inthe counting ring is connected back to the first stage. For example, ifthe ring were a three-stage counting ring, the back connection from thethird stage to the first stage will be made by connecting the conductorsA-A, B, and CC' from stage #3, back to the corresponding conductorsA--A', B, C-C of the first stage.

From the foregoing description it will be seen that, depending upon thenumber of impulses received, one and only one of the correspondingmagnetrons will be in its fired or upper stable conductive operatingstate. For example, if three impulses have been received only magnetron10 is in this upper stable conductive state, thus providing theequivalent to a storage of the numeral 3.

While one particular system has been described for using the doublestable magnetron conducting tube, it may be used in other similarsystems wherein the two stable conditions are to be selectivelycontrolled by applied signal pulses.

Various changes and modifications may be made in the disclosedembodiments without departing from the spirit and scope of theinvention.

What is claimed is:

1. An impulse storage system, comprising at least three magnetron tubesof the concentric anode-cathode kind, magnetic field-producing means foreach tube to selectively shift each tube from a low stable anode-cathodecurrent condition to a higher anode-cathode current condition inresponse to successive received impulses to be stored, each tube havinga priming winding, a holding winding, a firing winding, and a defiringwinding, means connecting all the firing windings to an impulsereceiving line, means connecting the holding winding of the first tubein series with the priming winding of the second tube, means connectingthe priming winding of the third tube with the defiring winding of thefirst tube whereby in response to each successive impulse from said lineonly a corresponding one of said tubes is shifted to its higher stablecurrent condition while simultaneously priming the next succeeding tubeand defiring the next preceding tube.

2. An impulse storage system, comprising a chain of magnetron tubes eacharranged to selectively assume a low and high stable anode-cathodecurrent condition under control of a composite coaxial magnetic field,means to set up said field including a set of four coaxial windings foreach tube, one winding being a priming winding, another a holdingwinding, another a firing winding, and another a defiring winding, meansconnecting the priming winding of each tube in series with the holdingwinding of a preceding tube, means coupling the defiring winding of eachtube with the primary winding of the second succeeding tube, a commonimpulse supply circuit connected to the firing winding of each tube,

6 said windings producing a composite magnetic field whereby in responseto successive received impulses applied to said firing windings eachtube is successively shifted from its low stable current condition toits high stable current condition while the next preceding tube isdefired and the next succeeding tube is primed.

3. An impulse counting system, comprising a series of chain connectedmagnetron tubes each having a set of magnetic windings, comprising apriming winding, a firing winding, a holding winding, a defiring windingfor selectively shifting each tube in succession from one stableanode-cathode current condition to another stable anode-cathode currentcondition and for holding it in said other stable condition after thecessation of a received impulse to be counted, means connecting thefiring windings to an impulse receiving line, means connecting theholding winding of each tube with the priming winding of the nextsucceeding tube, means including said line to energize all said firingwindings simultaneously by each successively received impulse wherebyeach tube in succession is shifted to a high stable current conditionwhile the preceding tube is shifted to a low stable current conditionand the succeeding tube is primed ready to be shifted to its high stablecurrent condition in response to the next received impulse, means toderive a defiring pulse from the shift of one tube to a higher stablecondition, and means to apply said defiring pulse to the defiringwinding of the next preceding tube.

4. An impulse storage system, comprising at least three magnetron tubesof the concentric cathode-anode kind, each tube having four separatefield-producing means each in magnetic field reacting relation with thespace between the cathode and anode of the respective magnetron tube,the first of said means being a winding arranged for continuousenergization from a source of direct current for normally maintainingthe tube at substantially cathode-anode space current cut-off, thesecond of said means being a winding arranged for connection in serieswith the anode-cathode and energized by the space current flowtherebetween, the third of said means being a winding for connection toa source of impulses for energizing said third means to produce amagnetic field which opposes the magnetic field produced by the firstmeans and thereby to prime the tube to a lower stable state of spacecurrent flow, the fourth means being a winding arranged to assist thethird means to fire the space current flow to a higher stable state,circuit connections connecting the fourth means of the third tube to animpulse producing circuit for producing a de-firing impulse derived fromthe shifting of the space current of the second tube from its lowerstable value to its higher fired value, and additional circuitconnections for applying the said de-firing impulse to the third meansof the first tube to restore said first tube to a de-fired space currentstable condition.

References Cited in the file of this patent UNITED STATES PATENTS1,536,809 Potts May 5, 1925 1,669,154 Baker May 8, 1928 1,807,097 BoddeMay 26, 1931 1,807,098 Bodde May 26, 1931 2,130,132 Hellman Sept. 13,1938 2,235,767 Luck Mar. 18, 1941 2,432,748 Glass Dec. 16, 19472,433,237 Rajchman et al. Dec. 23, 1947

